A fisherman's bobber is a device which when secured to a fishing line disposed in water will float on the surface of the water and will bob up and down when a fish takes a hook at the end of the line. Conventional bobbers are relatively expensive and must be assembled using five or more metal and plastic parts.
The present invention is directed toward a hollow plastic bobber which can be molded inexpensively as a single piece unit. Moreover, uniquely, the bobber can removably contain heavier than water material and used as a sinker. The bobber action can be readily restored by removing the material.